This invention relates to placing electronic components on circuit boards.
Electronic components can be supplied to component placement machines on carrier tapes spooled onto reels for removal by a pickup member and subsequent placement onto a destination circuit board. When the available inventory on a reel of component tape at a particular feeder is nearly exhausted, a machine operator might splice a leading end of a new component tape to the trailing end of the nearly exhausted tape, so that the machine will not run out of inventory and will continue to operate without interruption. Electronic component feeders, such as the one disclosed in Gfeller et al. (U.S. Pat. No. 6,157,870), have included a splice sensor for detecting a spice that connects two tapes together and for emitting, upon detection of that splice, a signal that allows for an automatic and synchronous take over of data associated with the connected tape.
Many component reels include a cover tape that overlays the components and is peeled away from the carrier tape before the components are picked from the carrier tape for assembly onto boards. In such cases, when splices are made, the carrier tape and the cover tape may both be spliced together at the connection.
One aspect of the invention features associating a component source with a destination circuit board in a component placement machine equipped with a component carrier tape having a first portion positioned to deliver components for subsequent placement onto the destination circuit board and a second portion attached to the first portion by a splice. The method includes sequentially removing a plurality of components from the component carrier tape for subsequent placement onto a destination circuit board, beginning with the first portion of tape, scanning a section of the component carrier tape associated with each removed component using a scanner that is responsive to the splice and, finally, creating an association between the destination circuit board and the second portion of tape in response to the scanner detecting the splice.
In certain embodiments, the scanner will be integral to a feeder to which the component carrier tape is coupled. In other embodiments, the scanner will be securely attached to a movable pick-head that is positionable to remove components from the component carrier tape. The scanner may be responsive to a property associated with the splice, for example, color, reflectivity, fluorescence, or even magnetic properties.
Additionally, in some cases, the method includes storing the identification data associated with the destination circuit board and the second portion of tape. A link can then be established between the identification data of the destination circuit board and the identification data of the second portion of tape. This link can be stored in a memory storage unit.
According to a second aspect of the invention, a method of tracking an association between a circuit board assembled with a component placement machine and a source identity of an electronic component of the circuit board includes coupling a first circuit board to the placement machine to receive an electronic component placed by the machine, mounting a reel loaded with a first length of component supply tape on the machine, attaching a leading end of a second length of component supply tape to a trailing end of the first length of component carrier tape with a splice connection, recording identities of the first length of tape, the second length of tape and the first circuit board, removing a component from the first length of tape and placing it on the first board, associating the identity of the first length of tape with the identity of the first board, detecting the splice connection, removing a component from the second length of tape for placement onto the first board and, finally, associating the identity of the second length of component carrier tape with the identity of the first board. In some cases, the method includes coupling a second circuit board to the machine to receive an electronic component placed by the machine, recording an identity of the second board, removing a component from the second length of tape for placement onto the second circuit board and associating the identity of the second length of tape to the identity of the second board.
The sequence of events may be modified in many ways as would be understood by one of skill in the art. For example, recording the identity of the first length of tape may occur before mounting the reel. Additionally, recording the identity of the second length of tape can occur before attaching the leading end of the second length of tape to the trailing end of the first length of tape. Furthermore, recording the identity of the first circuit board may be accomplished before coupling the first circuit board to the machine. Still further, removing the component from the first length of tape and associating the first length of tape with the first circuit board may occur before attaching the leading end of the second length of tape to the trailing end of the first length of tape. Also, associating the second length of tape to the first circuit board may occur in response to detecting the splice connection. Alternately, removing the component from the second length of tape after detecting the splice connection may trigger associating the second length of tape with the first circuit board.
In certain implementations the disclosed method includes associating the second length of tape to the first circuit board in response to placing a removed component from the second length of tape onto the first circuit board.
In some cases, the method includes activating an alarm or de-energizing the machine in response to detecting the splice connection if the identity of the second length of tape has not been recorded or has been recorded incorrectly.
Detecting the splice connection can be accomplished using a sensor that is integral to a feeder upon which the reel is mounted. Alternately, detecting the splice connection can be accomplished using a sensor that is securely fastened to a movable pickup member that is positionable for removing a component from the first length of tape and placing the removed component onto the first circuit board. Detecting the splice connection can include using an optical sensing element responsive to color to detect a color associated with the splice connection, or using an optical sensing element responsive to reflectivity to detect a reflectivity associated with the splice connection, or using an optical sensing element responsive to fluorescence to detect a fluorescence associated with the splice connection. Alternately, detecting the splice can include using a sensing element responsive to magnetism to detect a magnetic property associated with the splice connection.
According to yet another aspect of the invention, an apparatus includes a memory storage unit and a processing unit. The processing unit is configured to store in the memory storage unit identification data associated with a first circuit board, a first length of tape coupled to a placement machine to supply components thereto and a second length of tape having a leading end that is attached to a trailing end of the first length by a splice connection. The processor is also configured to create an association between the identification data of the second tape and the identification data of the first board in response to receiving a signal that indicates detection of the splice connection. In some instances, the recited apparatus includes a data entry device for receiving identification data associated with circuit boards and component carrier tape for processing in the processing unit and for storing in the memory unit. In some embodiments the processing unit is configured to store in memory data representing the association between the lengths of tape and the circuit boards. The processing unit can also be capable of creating the association after issuing an instruction to the placement machine to remove a component from the second length of tape for subsequent placement and after receiving the splice detection signal. The processing unit can also store in memory identification data associated with a second circuit board coupled to the placement machine and create an association between that data and the data associated with the second length of tape. The processing unit can also store the created association between the second length of tape and the second circuit board in a memory unit.
In still another aspect, a computer-readable medium stores computer executable instructions that cause a computer system to receive identification data associated with a first circuit board and identification data associated with a second length of tape that is attached to a first length by a splice connection. The instructions cause the computer system to store that identification data in a memory unit and to create an association between the first circuit board and the second length of tape in response to detecting a splice connection at the tape.
Some implementations include instructions that cause the computer system to store the created association. In some implementations the instructions also cause the computer system to store identification data associated with a second circuit board that is coupled to the placement machine and to create an association between the second circuit board and the second length of tape. Additionally, in some implementations, the instructions can cause the computer system to store the created association.
According to still another aspect, a method of managing inventory data associated with an electronic component placement machine having a pick-up member and a plurality of feeder positions includes removing an electronic component from a feeder at a selected one of the feeder positions with the pick-up member for subsequent placement on a circuit assembly. The method also includes scanning a portion of a component carrier tape associated with the selected feeder position using a scanner secured to the pick-up member. Additionally, the method includes determining whether the scanned portion of the component carrier tape includes a splice.
In some embodiments, the method also includes placing the removed electronic component on the circuit assembly, removing a second electronic component from the feeder and scanning a second portion of the component carrier tape for a splice, the second portion of the carrier tape spaced from all previously scanned portions. In some embodiments, the recited method also includes placing the removed electronic component on the circuit assembly, removing a second electronic component from a second feeder with the pick-up member, scanning a portion of a component carrier tape associated with the second feeder using the scanner secured to the pick-up member and determining whether the scanned portion of the component carrier tape associated with the second feeder includes a splice. Furthermore, in some implementations, the method includes, after scanning the portion of the component carrier tape, advancing the component carrier tape. Data associated with a particular feeder position that is stored in an inventory management database can also be verified and/or updated upon detection of a splice. A signal can be generated to indicate that the scanned portion of component carrier tape includes a splice. In certain situations, the method includes incrementing a value stored in a memory device responsive to the generated signal, where the stored value indicates the remaining inventory of electronic components available at the selected feeder position. Certain implementations will include, verifying, in response to the generated signal, that component identification data is updated in an inventory control database associated with the electronic component placement machine. In certain implementations, the placement machine will be de-energized in response to the generated signal and a determination that component identification data is not updated. Furthermore, in such a case, an alarm can be activated as well.
Some implementations include detecting a particular property of the scanned portion of the component carrier tape with a scanner that has an optical sensing element responsive to color, reflectivity or fluorescence. Alternately, the scanner can have a sensing element responsive to magnetism. Certain implementations include scanning a base portion of the component carrier tape or a separable cover portion of the component carrier tape.
According to another aspect, an electronic component placement machine includes a series of feeder slots adapted to receive and hold electronic component feeders containing discrete electronic components carried in spaced relation on carrier tapes, a circuit board holder, a pick head movable between selected feeder slots for sequentially picking the discrete electronic components from their respective feeders and transporting them to the circuit board holder for placement, and a splice detector secured to the pick head for movement therewith between feeder slots. The splice detector is arranged to be functionally directed toward a selected region of the carrier tape of a selected feeder from which the pick head is positioned for picking a component. In certain embodiments, the splice detector is operable to detect a splice at the selected region of the carrier tape.
In some embodiments, the electronic component placement machine includes an inventory management database for storing data associated with the discrete electronic components available at each feeder slot. Such data can include, for example, an available inventory value associated with each feeder position, which value is typically updated each time the pick head picks a discrete electronic component from the particular feeder position. The available inventory value can be decremented, for example, each time the pick head picks a discrete electronic component from an associated feeder position as long as the splice detector does not detect a splice at the selected region of the carrier tape. Additionally, the available inventory values can be replenished each time the splice detector detects a splice at the selected region of the carrier tape.
Certain implementations include an inventory management database for storing component identification data associated with the discrete electronic components available at each feeder slot. Certain placement machines also include a verification unit, wherein, upon detection of a splice by the splice detector, the verification unit verifies that the component identification data has been properly updated. Particular embodiments include an alarm that is operable in response to the splice detector detecting a splice.
The splice detector can include an optical sensing element responsive to a color, reflectivity, fluorescence, or other property associated with a splice on the carrier tape. Alternately, the splice detector can include a sensing element responsive to a magnetic property associated with a splice. Additionally, the splice detector can be functionally directed toward either a base portion of tape or a removed cover portion of tape.
Certain placement machines include a signal generator that can generate a signal in response to the splice detector detecting a splice.
According to yet another aspect, an electronic component placement machine has a plurality of electronic component feeder positions and includes a pick-up member positionable to remove an electronic component from a component carrier tape at a selected one of the plurality of feeder positions and a scanner secured to the pick-up member. The scanner is positionable to scan a portion of the component carrier tape associated with the selected feeder position, and is responsive to a splice on the scanned portion of the component carrier tape. The placement machine also typically includes a mechanism for advancing the component carrier tape after the portion of the component carrier tape is scanned.
In some cases, the recited placement machine includes an inventory management database for storing data associated with the electronic components accessible at each of the feeder positions. The inventory management database can store values representing the remaining inventory of electronic components available at each feeder position. Additionally, the values can be automatically updated upon detection of a splice on the component carrier tape to indicate availability of additional electronic components at selected feeder locations.
In certain implementations, the placement machine includes a verification unit that can verify that the component identification data associated with the feeder positions is properly updated upon detection of a splice. In certain instances, the placement machine can also include an alarm that is operable in response to the scanner detecting a splice on the component carrier tape.
The scanner can include an optical sensing element responsive to a color, reflectivity or fluorescence associated with a splice connection. Alternately, the scanner can include a sensing element responsive to a magnetic property associated with the splice connection. The scanner can be positionable to scan either a base portion of the carrier tape or a cover portion of the carrier tape. In some implementations, the placement machine can include a signal generator that generates a signal in response to the scanner detecting a splice on the scanned portion of the component carrier tape.
Aspects of the invention can provide improved traceability to component sources associated with a circuit board manufactured by a component placement machine. This improved traceability may provide, for example, a simpler way to recall a large number of circuit boards xe2x80x9cinfectedxe2x80x9d by a component supplied from a defective reel of carrier tape. Such facilitated recall capability may be especially desirable in many industries such as medical, avionics, automotive, military, etc. where, for example, product liability is a significant concern or where proper operation of equipment is particularly crucial.
Additionally, the detection of splices in a component placement machine equipped with a plurality of component carrier tapes may be simplified, for example, by utilizing a single detector secured to a movable pickup member. Implementing such techniques may significantly reduce the number of hardware components that a placement machine uses and simplify the interconnections between those components, ultimately resulting in lower manufacturing costs associated with the component placement machine. Implementing such techniques may also facilitate troubleshooting of operational problems associated with a placement machine. Furthermore, maintenance costs may be reduced, and placement machines may operate more efficiently.
Improvements and simplifications may also be realized in the process of verifying that a spliced length of tape contains correct components mounted thereon for a particular application. Furthermore, other improvements and simplifications of functions related to splice detection may also be realized.
Other features and advantages will be readily apparent from the following detailed description, the accompanying drawings and the claims.